Custom vacuum forming machines are available on the market for molding articles from sheets of plastic. Such machines generally are employed for forming articles on a limited production basis. The known prior machines are controlled manually by a plurality of toggle switches or automatically by a fixed automatic system. The disadvantages of the manually controlled machine is that it is difficult to duplicate a desired sequence of steps with such a machine. The known automatic machines have disadvantages in that their operating steps are fixed or cannot be changed easily whereby such machines are not very versatile.